/*
 * Copyright (C) 2012-2020 Markus Junginger, greenrobot (http://greenrobot.org)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.greenrobot.eventbus.util;

import org.greenrobot.eventbus.Logger;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;
import java.util.Set;
import java.util.logging.Level;

/**
 * Maps throwables to texts for error dialogs. Use Config to configure the mapping.
 *
 * @author Markus
 */
public class ExceptionToResourceMapping {

  public final Map<Class<? extends Throwable>, Integer> throwableToMsgIdMap;

  public ExceptionToResourceMapping() {
    throwableToMsgIdMap = new HashMap<>();
  }

  /** Looks at the exception and its causes trying to find an ID. */
  public Integer mapThrowable(final Throwable throwable) {
    Throwable throwableToCheck = throwable;
    int depthToGo = 20;

    while (true) {
      Integer resId = mapThrowableFlat(throwableToCheck);
      if (resId != null) {
        return resId;
      } else {
        throwableToCheck = throwableToCheck.getCause();
        depthToGo--;
        if (depthToGo <= 0 || throwableToCheck == throwable || throwableToCheck == null) {
          Logger logger = Logger.Default.get(); // No EventBus instance here
          logger.log(Level.FINE, "No specific message resource ID found for " + throwable);
          // return config.defaultErrorMsgId;
          return null;
        }
      }
    }
  }

  /** Mapping without checking the cause (done in mapThrowable). */
  protected Integer mapThrowableFlat(Throwable throwable) {
    Class<? extends Throwable> throwableClass = throwable.getClass();
    Integer resId = throwableToMsgIdMap.get(throwableClass);
    if (resId == null) {
      Class<? extends Throwable> closestClass = null;
      Set<Entry<Class<? extends Throwable>, Integer>> mappings = throwableToMsgIdMap.entrySet();
      for (Entry<Class<? extends Throwable>, Integer> mapping : mappings) {
        Class<? extends Throwable> candidate = mapping.getKey();
        if (candidate.isAssignableFrom(throwableClass)) {
          if (closestClass == null || closestClass.isAssignableFrom(candidate)) {
            closestClass = candidate;
            resId = mapping.getValue();
          }
        }
      }
    }
    return resId;
  }

  public ExceptionToResourceMapping addMapping(Class<? extends Throwable> clazz, int msgId) {
    throwableToMsgIdMap.put(clazz, msgId);
    return this;
  }
}
